Multiple plug feeding and ejecting conduit head



July 26, 1955 R. c. BAKER 2,713,909

MULTIPLE PLUG FEEDING AND EJECTING CONDUIT HEAD Filed Dec. 15, 1952 2445 ezusz/v c. amaze INVENTOR.

BY /4 M Ma AWTQENEFS United States Patent MULTIPLE PLUG FEEDING ANDEJECTIN G CGNDUIT HEAD Reuben C. Baker, Coaliuga, Calif., assignor toBaker Oil Tools, Ine., Los Angelcs, Califi, a corporation of CaliforniaApplication December 13, 1952, Serial Na. 325,868

15 Claims. (Cl. 166-70) The present invention relates to well apparatus,and more particularly to tubing or conduit heads for introducingcementing plugs, and the like, into a conduit string disposed in a Wellbore.

In the pumping of cementitious material, such as cement slurry andsynthetic resins, into a well bore, contamination of the charge ofcementitious material by the fluid in the well conduit preceding andfollowing it can be prevented by the use of one or more separating plugsdisposed at the upper or lower ends of the cementitious material, or atboth ends. In introducing the plug or plugs in the conduit string, theinlet of the head at the upper end of the latter has been disconnected,the plug introduced, and the inlet reconnected, to enable the plug to bepumped down the conduit str'mg. This unsatisfactory procedure ismagnified when a plurality of plugs are to be inserted in the conduitstring at difierent times.

Accordingly, it is an object of the present invention to provide animproved apparatus for introducing a plug into a conduit string, whendesired, without disconnecting the hydraulic connections to theapparatus.

Another object of the invention is to provide an apparatus capable ofeffecting individual introduction of a plurality of plugs into a conduitstring, when desired, without disconnecting the hydraulic connections tothe apparatus.

A further object of the invention is to provide an apparatus thatenables an unlimited number of plugs to be introduced individually intoa conduit string, without disconnection of the hydraulic lines leadingto and from the apparatus.

Yet another object of the invention is to provide an apparatus capableof efiecting introduction of a plurality of plugs into a conduit string,which is compact, positive in its operation, and in which hydraulicforces in the apparatus do not eflect its operation, since they balanceor neutralize themselves.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration of a formin which it may be embodied. This form is shown in the drawingsaccompanying and forming part of the present specification. It will nowbe described in detail, for the purpose of illustrating the generalprinciples of the invention; but it is to be understood that suchdetailed description is not to be taken in a limiting sense, since thescope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a longitudinal section through an apparatus embodying theinvention, taken along the line 1-1 in Fig. 2, and on an enlarged scalewith respect to Fig. 2;

Fig. 2 is a top plan view, on a reduced scale, of the apparatusdisclosed in Fig. l;

Fig. 3 is a cross-section, on a reduced scale, taken along the line 33on Fig. 1;

Fig. 4 is a fragmentary longitudinal section, on an enlarged scale,taken along the line 44 on Fig. 2.

The apparatus disclosed in the drawings is capable of vented by asuitable side seal 28 in the upper and lower trunnions 22,

effecting introduction of one or a plurality of plugs into a conduitstring, such as a tubing string, disposed in a well bore, and connectedwith a mechanism (not shown) in the well bore. The apparatus actuallyconstitutes a conduit or tubing head H having a pressure inlet pipe orsub 10 secured to its upper portion, and a discharge pipe or sub 11secured in its lower portion. These two pipes are in alignment, so thatfiuid under pressure introduced into the inlet pipe 10 can pass throughthe apparatus and out through the discharge pipe 11. The fluid underpressure is also effective to pump plugs that may be disposed inalignment with the pipes out of the tubing head H and on through thedischarge pipe 11, in a manner described hereinafter.

The conduit or tubing head H includes a housing 12 that may include agenerally cylindrical wall 13 having a lower closure member 13a threadedinto its lower end and an upper closure member 14 threaded into itsupper end. These two closure members may be secured in place by suitablelock screws 15 extending through the housing wall 13 and into theclosure members 13a, 14. In addition, fluid leakage from the interior ofthe housing 12 and through the threaded connections between the wall andthe closure members can be prevented by suitable side seals 16 on theclosure members engaging the inner wall 13 of the housing.

The pressure inlet pipe or sub 10 is threaded into the upper closuremember 14 at one side of the axis of the apparatus, whereas thedischarge pipe or sub 11 is threaded into a depending extension 17 ofthe lower closure member 130, and in alignment or coaxial relation tothe inlet pipe 10. As described below, a plug can be placed in alignmentwith the inlet and discharge pipes 10, 11 whenever it is to be ejectedinto the discharge pipe 11.

The wall 13 and closure member 13a, 14 together provide a space orchamber 18 in which a barrel or cylinder 19 is disposed. This barrel orcylinder is rotatable about the axis of the apparatus by piloting itslower trunnion 20 into a companion socket 21 in the lower closure 13a,its upper trunnion 22 extending through a hole 23 in the upper closuremember 14 and projecting above the latter, for reception of a suitableoperating handle 24 that may be removably secured to the upper trunnionby a key 25 fitting in the upper trunnion and received in a keyway 26 inthe hub portion 27 of the handle member 24. Leakage of fluid outwardlyalong the lower trunnion 20 is prethis trunnion engaging the wall of thesocket 21, whereas leakage of fluid in the opposite direction along theupper trunnion 22 is prevented by a side seal 29 carried on the latterand engaging the closure wall defining the hole or bore 23 through whichthe trunnion passes.

The lower trunnion 20 rests upon a bearing disc or plate 30, for thepurpose of reducing frictional resistance to rotation of the cylinder 19in the housing 12. This bearing disc is supported by the lower end 31 ofthe socket 21, and has a hole 32 therewithin in alignment with a hole 33extending through the lower closure member 13a to its exterior. Theholes 32, 33 are provided, so that 20 are acted upon by atmosphericpressure acting over the cross-sectional areas of the trunnions, whichare made of the same diameter, to balance the efliect of atmosphericpressure on the trunnions. Fluid under pressure entering the apparatusthrough the pressure inlet pipe 10 will have no efliect on forcing thecylinder or barrel 19 in an upward or downward direction, since it isacting against the upper end of the barrel over the same cross-sectionalarea as against the lower end of the barrel. Accordingly, the hydraulicforce tending to shift the barrel or cylinder 19 downwardly iscounterbalanced by the hydraulic force tending to shift the barrel orcylinder in an upward direction.

The chambers 35 themselves are also equi-angularly disposed with respectto one another. As disclosed, a liner 36 defines each chamber, the linerhaving an upper flange 37 seating within a counterbore 38 in thecylinder and engaging a shoulder 39 forming the lower end of thecounterbore. The liner is provided for a particular size of tubing plugP, to be used in the apparatus. However, if a large tubing plug is to beused, then the liners 36 will be removed and the effective diameter ofeach plug chamber 35 will be increased accordingly. As an example, witha liner 36 in place, the effective diameter of the chamber 35 can beapproximately two inches, to receive a two-inch diameter tubing plug P.Upon removal of the liner, each chamber 35 will then have an eifectivediameter of about two and one-half inches for the reception of a two andone-half inch diameter tubing plug P.

As mentioned above, the aligned inlet and discharge pipes 10, 11 aredisposed to one side of the axis of the cylinder 19. The discharge pipecommunicates with a pressure inlet opening 40 in the upper closuremember 14, the discharge pipe 11 communicating with an outlet opening 41in the lower closure member 13a, which is in alignment with the inletopening 40. The common axis of the inlet and outlet openings 40, 41 isspaced the same radial distance from the axis of rotation of thecylinder or barrel 19, as the axes of the plug chambers in the barrel.Accordingly, the barrel can be rotated to place each of its chambers 35in alignment with the pressure inlet and outlet openings 40, 41.

The chambers may be so located and held in such location by a locking ora retaining device. Thus, the upper closure member 14 may have aplurality of recesses or holes 42 opening upwardly through its upper endthat are equi-angularly spaced from each other. The lever arm or handlemember 24 may have a hole 43 the same radial distance from therotational axis of the cylinder 19 as the other holes 42. A lock orretainer pin 44 is inserted through the lever arm hole 43 and can bereceived within any one of the holes 42 in the upper closure member 14.

When the handle member 24 has been turned to rotate the cylinder 19, andwhen the handle hole 43 and one of the other holes 42 are in alignment,a plug chamber 35 will then be in alignment with the inlet and theoutlet openings 46, 41 through the upper and lower closure members 14,13a. In this way, the lever arm 24 may turn the cylinder 19, uponremoving the lock or retainer pin 44 from an upper closure hole 42, andthe pin inserted in one of the other holes 42. Upon insertion of the pinin each hole, the operator is assured that a plug chamber 35 is inalignment with the inlet and outlet openings 40, 41. Of course, the lockor retainer holes 42 in the closure member 14 conform in number andspacing to the number of chambers 35 in the cylinder or barrel 19, sothat the lever arm 24 may be turned and its lock pin 44 insertedprogressively into each hole, with assurance that the plug chambers 35will be rotated progressively into alignment with the inlet and outletopenings 40, 41.

In order to clear the pressure inlet pipe 19, the handle or lever armmember 24 is made of L shape, as disclosed in full lines in Fig. 2. Withsuch shape, it is not possible to rotate the cylinder 19 through 360degrees, since the lever arm 24 will engage the opposite side of thepressure inlet pipe 10 before that extent of rotation has been achieved.However, by providing the angular or L shape of the lever arm, it canfirst be used in the full line position disclosed in Fig. 2, until thecylinder 19 has been rotated a partial revolution, whereupon it can heslipped endwise off the key 25 and upper trunnion 22, and then turnedover so that its initial upper face is then disposed in a downwarddirection, whereupon the handle member 24 can again be replaced on theupper trunnion 22 with the key 25 disposed within the handle keyway 26.When this is done, the handle 24 will occupy the broken line positiondisclosed in Fig. 2, which will then allow it to turn the barrel orcylinder 19 to the extent required, the L shape of the handle memberavoiding interference by the pressure inlet pipe 10.

When one of the plug chambers 35 is aligned with the pressure inlet andoutlet openings 40, 41, another plug chamber is aligned with an entranceopening in the upper closure member 14, through which the plugs P can beinserted in each chamber 35. This entrance opening can be closed bythreading a plug 51 thereinto, the upper end of the plug preferablybeing flush with the upper end of the closure member 14, to avoidinterference with movement of the lever arm or handle 24. The plug 51can be rotated for the purpose of threading it into the entrance opening50, or removing it therefrom, by the provision of a suitable tool (notshown) in the noncircular recess 52, which may be of hexagonal shape, inthe upper end of the plug. In addition, leakage of fluid through thethreaded connection between the plug 51 and the upper closure member 14may be prevented by a suitable side seal 53 on the plug engaging theclosure wall defining the entrance opening 50.

In using the apparatus, all of the plug chambers 35, with the exceptionof one, may have tubing plugs P of any desired type inserted therewithinby removing the entrance plug 51 and rotating the cylinder 19 to disposevarious chambers 35 in alignment with the entrance opening 50. In thespecific device disclosed in the drawings, there are five plug chambers,so that four of such plug chambers will have rubber or other types ofplugs P inserted therein, by successively rotating the cylinder to placethe chambers 35 in alignment with the entrance opening 59.

After the cylinder 19 has been loaded with the rubber plugs l, theentrance plug 51 is replaced, to close the entrance opening 50. Thedischarge pipe 11 can be connected to the upper end of the tubing, orother conduit string, disposed in the well bore, and the necessaryconnections made to the pressure inlet pipe from the pumping mechanismdisposed at the top of the well bore. The cylinder 19 is rotated so thatthe particular chamber 35 that is devoid of a plug P is in alignmentwith the inlet and outlet openings 46, 41, which chamber may correspondwith the zero lock hole position disclosed in Fig. 2. The lock pin 44-can then be inserted through the lever arm hole 43 and this lock hole42, to assure the alignment of the empty chamber 35 with the inlet andoutlet openings 40, 41. Loss of the lock pin, when removed from theholes 42, 43, may be prevented by attaching a chain to an eye 61 of thepin 44 and securing its other end to the outer portion of the handle orarm 24.

Fluid may now be pumped down through the inlet pipe 10, empty plugchamber 35 and discharge pipe 11. As an example, the fluid may becirculated down through the parts just referred to for a continuedpassage down through the tubing string in the well bore, for the purposeof conditioning the latter. If it is desired to introduce a charge ofcement slurry, or synthetic resin, into the tubing string in the wellbore, the charge can be pumped toward the pressure inlet pipe 10, and,when it reaches such pipe, the lock pin 44 is removed from a companionlock hole 42 and the handle 24 and cylinder 19 rotated a partialrevolution until the lock pin is disposed in alignment with another lockhole 42, such as the number 1 hole 42, shown in Fig. 2, into which thelock pin 44 is then inserted. Such partial rotation positions a tubingplug P in another chamber 35 in alignment with the pressure inlet andoutlet openings 40, 41, whereupon the pressure of the fluid in the inletpipe will force the plug P out of such chamber in which it is contained,and into the discharge pipe or sub 11, this plug then proceedingdownwardly through the tubing string ahead of the cementitious materialthereabove, in order to prevent contamination of the cementitiousmaterial by the preceding liquid in the tubing string.

When the upper end of the charge of cementitious material is at or nearthe pressure inlet opening 40, the lock pin 44 can be removed from thenumber 1 lock hole 42 and the handle member 24 rotated again toward thenumber 2 lock hole position, the lock pin then being inserted in thisnumber 2 hole 42, which insures the alignment of the next chamber 35 inthe barrel 19 with the inlet and outlet openings 40, 41. When suchalignment occurs, the pressure in the inlet pipe 10 will force the plugP out of its chamber 35 and ejects it into the discharge pipe 11, forcontinued passage down through the tubing string on top of the charge ofcementitious material. This plug prevents contamination of thecementitious material by the displacement fluid in the conduit stringand apparatus above it.

Whenever desired, succeeding plugs P in the cylinder chambers 35 can bebrought into alignment with the inlet and outlet openings 40, 41, byrotating the cylinder or barrel 19, the aligned position being assuredupon inserting of the lock pin 44 in the respective lock holes 42 in theupper closure member 14, until all of the plugs have been ejected. Ofcourse, during rotation of the barrel 19 in the same direction, theposition of the handle 24 will eventually have to be reversed to thatshown in broken lines in Fig. 2.

As plugs P are ejected from each chamber 35 and out through the outletopening 41 and discharge pipe 11, additional plugs P can be loaded intoempty cylinder chambers. All that need be done is to relieve thepressure in the pressure inlet pipe 10 and remove the entrance plug 51,which then allows additional tubing plugs to be inserted through theentrance opening 50 and into the empty barrel chambers 35. When thechambers have been reloaded or refilled with plugs, the entrance plug 51can again be threaded into the closure member 14, to close the entranceopening. In this manner, an unlimited number of plugs may be disposed inthe apparatus for ejection from the head H and into the conduit string,without disconnecting any of the hydraulic lines leading to and from theapparatus.

It is, accordingly, apparent that an apparatus has been provided whichenables one or a number of plugs P to be introduced into a conduitstring, whenever desired, without disconnecting the hydraulic linesleading to the apparatus. A plurality of plugs can be introducedindividually whenever desired, and the number of plugs is unlimited, inview of the ability to reload the apparatus. The apparatus is compactand positive in its operation, since the chambers 35 can be placed inexact alignment with the inlet and outlet openings 40, 41. In addition,the cylinder 19 can be rotated freely, since the pressure within theapparatus is balanced at all times, thereby precluding the presence ofany unbalanced hydraulic pressures that might tend to shift the cylinder19 axially in one longitudinal direction or the other.

The inventor claims:

1. In apparatus of the character described: a housing structure having afluid inlet and a fluid outlet spaced from each other; a holder movablein said housing structure and having a chamber adapted to receive aplug; and means for shifting said holder in said housing structure toplace said chamber in one position into alignment with said inlet andoutlet and in another position out of alignment with said inlet andoutlet.

2. In apparatus of the character described: a housing structure having afluid inlet and a fluid outlet; a holder movable in said housingstructure and having a chamber adapted to receive a plug; said housingstructure having an entrance opening through which a plug can beinserted in said chamber; removable means closing said opening; andmeans for shifting said holder in said housing structure to place saidchamber selectively in alignment with said entrance opening or inalignment with said outlet and between said inlet and outlet.

3. In apparatus of the character described: a housing structure having afluid inlet and a fluid outlet spaced from each other; a holder movablein said housing structure and having a chamber adapted to receive aplug; means for shifting said holder in said housing structure to placesaid chamber in one position into alignment with said inlet and outletand in another position out of alignment with said inlet and outlet; andmeans for selectively retaining said holder with its chamber in or outof alignment with said outlet.

4. In apparatus of the character described: a housing structure having afluid inlet and a fluid outlet spaced from each other; a holder movablein said housing structure and having a plurality of spaced chambersadapted to receive plugs; and means for shifting said holder in saidhousing structure to selectively place each chamber in one position inalignment with said inlet and outlet and in another position out ofalignment with said inlet and outlet.

5. In apparatus of the character described: a housing structure having afluid inlet and a fluid outlet; a holder movable in said housingstructure and having a plurality of spaced chambers adapted to receiveplugs; said housing structure having an entrance opening through whichplugs can pass; removable means closing said opening; and means forshifting said holder in said housing structure to selectively place eachchamber in alignment with said opening or in alignment with said outletand between said inlet and outlet.

6. In apparatus as defined in claim 5, wherein said entrance opening andoutlet are spaced from each other such that alignment of one chamberwith said entrance opening locates another chamber in alignment withsaid outlet.

7. In apparatus of the character described: a housing structure having afluid inlet and a fluid outlet spaced from each other; a holderrotatably mounted in said housing structure and having a chamber adaptedto receive a plug; and means for rotating said holder in said housingstructure to locate said chamber in one position into alignment withsaid inlet and outlet and in another position out of alignment with saidinlet and outlet.

8. In apparatus of the character described: a housing structure having afluid inlet and a fluid outlet; a holder rotatably mounted in saidhousing structure and having a chamber adapted to receive a plug; saidhousing structure having an entrance opening through which a plug can beinserted in said chamber; removable means closing said opening; andmeans for rotating said holder in said housing structure to place saidchamber selectively in alignment with said entrance opening or inalignment with said outlet and between said inlet and outlet.

9. In apparatus of the character described: a housing structure having afluid inlet and a fluid outlet spaced from each other; a holderrotatably mounted in said housing structure and having a plurality ofcircumferentially spaced chambers adapted to receive plugs; and meansfor rotating said holder in said housing structure to selectively locateeach chamber in one position in alignment with said inlet and outlet andin another position out of alignment with said inlet and outlet.

10. In apparatus of the character described: a housing structure havinga fluid inlet and a fluid outlet; a holder rotatably mounted in saidhousing structure and having a plurality of circumferentially spacedchambers adapted to receive plugs; said housing structure having anentrance opening through which plugs can pass; removable means closingsaid opening; and means for rotating said holder in said housingstructure to selectively locate each rotatably mounted in said housingstructure and having a plurality of eircumferentially spaced chambersadapted to receive plugs, said holder having oppositely directedtrunnions rotatably supported in said housing structure, said trunnionsbeing substantially equal in cross-sectional area and being exposed toatmospheric pressure; and means for rotating said holder in said housingstructure to selectively locate each chamber in alignment with saidoutlet and between said inlet and outlet.

13. In apparatus of the character described: a housing structure havinga fluid inlet and a fluid outlet; a holder rotatably mounted in saidhousing structure and having a plurality of circumferentially spacedchambers adapted to receive plugs, said holder having oppositelydirected trunnions rotatably supported in said housing structure,

and means attached to one of said trunnions for rotating said holder insaid housing structure to locate each chamber in alignment with saidoutlet and between said inlet and outlet.

14. In apparatus of the character described: a housing structure havinga fluid inlet and a fluid outlet; a holder rotatably mounted in saidhousing structure and having n I.) a plurality of circumferentiallyspaced chambers adapted to receive plugs; said housing structure havingan entrance opening through which plugs can pass; removable meansclosing said opening; said holder having oppositely directed trunnionsrotatably supported in said housing structure; and means attached to oneof said trunnions for rotating said holder in said housing structure toselectively locate each chamber in alignment with said opening or inalignment with said outlet and between said inlet and outlet.

15. in apparatus of the character described: a housing structure havinga fluid inlet and a fluid outlet; a holder rotatably mounted in saidhousing structure and having a plurality of circumferentially spacedchambers adapted to receive plugs; said housing structure having anentrance opening through which plugs can pass; removable means closingsaid opening; said holder having oppositely directed trunnions rotatablysupported in said housing structure; means attached to one of saidtrunnions for rotating said holder in said housing structure toselectively locate each chamber in alignment with said opening or inalignment with said outlet and between said inlet and outlet; and meansfor selectively retaining said holder in various positions to which itis rotated in alignment with said outlet and entrance opening.

References Cited in the file of this patent UNITED STATES PATENTS

